I used to film forty-minute sessions. People told me they loved them. The numbers told me they finished about one in five.
What changed
I cut everything to ten minutes for a month as a test. Completion went from 22% to 81%, and people came back the next day.
Why it works
Ten minutes is short enough to start when you do not feel like it, which is the only kind of session that counts. The long ones are still here, for the days you do.